Charged particles are accelerated by a synchrotron and a particle beam, a bundle of high-energy charged particles which are emitted from the synchrotron, is used to treat cancer, for example. Regarding a particle beam for medical treatment, in some cases, it is preferable to select a kind of a particle beam depending on an object to be treated. Consequently, it is expected to configure one synchrotron accelerator system to enable to emit different kinds of particle beams. Synchrotrons accelerate charged particles that is, ions, which are injected, and in order to enable to emit different kinds of particle beams, a synchrotron injector system which injects different kinds of ions into a synchrotron is necessary.
Patent Document 1 discloses technology by which all kinds of ions can be accelerated to desired level of energy in the same synchrotron. Regarding an injector system for injecting ions into the synchrotron, it is stated such that an ion beam which is accelerated to a given level of energy by a pre-accelerator is injected.
Further, in Patent Document 2, it is stated such that in order to use a proton beam together with a carbon beam, ion sources which generate each of beams are necessary, however, the details regarding a pre-accelerator which injects ions into a synchrotron are not stated.
Further, Patent Document 3 discloses the configuration in which a particle beam such as protons of large current can be accelerated in an APF-IH linear accelerator.